Sentences with phrase «stable isotope ratios in»

This likely influences geographic variation in surface nutrient availability, and therefore stable isotope ratios in POM, primary producers [12] and consumers [14].

Early TRL projects focused on establishing long tree - ring records from temperature - sensitive boreal forest locations in North American for studies of global change, using dendrochronologically dated wood, to investigate the value of stable isotope ratios in cellulose as paleo - thermometers and developing the necessary computer software for processing the data.

Stable isotope ratios in atmospheric methane and carbon dioxide provide a window on the sources as well.

The team found that the degree of nitrogen pollution, which is worsening in urban areas, can be evaluated by analyzing the nitrogen content and the stable isotope ratio in bryophytes.

Not exact matches

Using spectroscopy, stable isotope ratios (carbon, nitrogen and sulphur) were investigated in the collagen of the bones, along with the ratio of strontium to calcium in the bone mineral.

Researchers linked dated graffiti about droughts in a cave in China to physical evidence in the cave of the water shortages, such as changes in ratios of stable isotopes in specific layers of stalagmites

«Laser ablation isotope ratio mass spectrometry for enhanced sensitivity and spatial resolution in stable isotope analysis.»

Qualitatively, the slow ventilation is consistent with very saline and very cold deep waters reconstructed for the last glacial maximum (Adkins et al., 2002), as well as low glacial stable carbon isotope ratios (13C / 12C) in the deep South Atlantic.

Comparison of stable carbon isotope ratios in the whole wood, cellulose and lignin of oak tree - rings Dr. Ron Towner from the Laboratory of Tree - Ring Research at the University of Arizona explains the principles behind dendrochronology and why this dating

It basically says that ringwidth is a function of: age trend + climate signal + endogenous (local) disturbances + exogenous (standwide) disturbances + unexplained variation Basically, this concept also underlies all other dendro proxies, be it maximum latewood density or stable isotope ratios, even though there are variations, e. g. age trend in density data is treated differently from ring width data).

This analytical document shows that stable isotope ratios can be used to monitor changes in the character of precipitation in response to periodic variability or changes in climate.

Stable carbon isotope ratios from tree rings record changes in the internal concentration of carbon dioxide and, in the northern Boreal zone, are regarded as a proxy for photosynthetic rate, and therefore summer sunshine.

Stable oxygen isotope ratios contained in the shell can be used to infer past water temperatures.

This proxy, known as the δ18O stable oxygen isotope ratio, varies in proportion to the ambient moisture.

The ratio of stable isotopes oxygen - 18 and oxygen - 16 in the foraminifera is an indicator of ocean temperature.

For example, extreme values of the ratio of stable isotopes in foraminifera from the eastern Pacific have previously been interpreted as ENSO activity, but modeling suggests that this interpretation may not always be suitable for past climates due to variability caused by other factors.

The size of the carbon injection is estimated from changes in the stable carbon isotope ratio 13C / 12C in sediments and from ocean acidification implied by changes in the ocean depth below which carbonate dissolution occurred.